NEUTRINO PHYSICS FROM PRECISION COSMOLOGY

STEEN HANNESTAD13 JULY - PPC 2010, TORINO

e

Fermion Mass Spectrum

1010 10010011 1010 10010011 1010 10010011 1010 10010011 1010 10010011 11meVmeV eVeV keVkeV MeVMeV GeVGeV TeVTeV

dd ss bbQ = Q = 1/31/3

uu cc ttQ = Q = 2/32/3

Charged LeptonsCharged Leptons ee

All flavorsAll flavors

33NeutrinosNeutrinos

132313231223121323122312

132313231223121323122312

1313121312

ccescsscesccss

csesssccessccs

escscc

Uii

ii

i

1212

1212

sin

cos

s

c

)(

)(

)(

33

22

11

m

m

m

Ue

FLAVOUR STATES PROPAGATION STATES

MIXING MATRIX (UNITARY)

FORTUNATELY WE ONLY HAVE TO CARE ABOUT THE MASS STATES

Normal hierarchy Inverted hierarchy

If neutrino masses are hierarchical then oscillation experimentsdo not give information on the absolute value of neutrino masses

However, if neutrino masses are degenerate

no information can be gained from such experiments.

Experiments which rely on either the kinematics of neutrino massor the spin-flip in neutrinoless double beta decay are the most efficient for measuring m0

catmospherimm 0

SOLAR KAMLAND

ATMO. K2KMINOS

LIGHTEST

INVERTED

NORMAL

HIERARCHICAL DEGENERATE

Tritium decay endpoint measurements have provided limitson the electron neutrino mass

This translates into a limit on the sum of the three mass eigenstates

(95%) eV 3.22/1

22 iei mU

eV 7im

Mainz experiment, final analysis (Kraus et al.)

em

THE ABSOLUTE VALUES OF NEUTRINO MASSESFROM COSMOLOGY

NEUTRINOS AFFECT STRUCTURE FORMATIONBECAUSE THEY ARE A SOURCE OF DARK MATTER(n ~ 100 cm-3)

HOWEVER, eV NEUTRINOS ARE DIFFERENT FROM CDM BECAUSE THEY FREE STREAM

1eVFS Gpc 1~ md

SCALES SMALLER THAN dFS DAMPED AWAY, LEADS TOSUPPRESSION OF POWER ON SMALL SCALES

eV 932

mh FROM K2

11

43/1

TT

N-BODY SIMULATIONS OF CDM WITH AND WITHOUT NEUTRINO MASS (768 Mpc3) – GADGET 2

eV 9.6m 0m

T Haugboelle, University of Aarhus

256Mpc

AVAILABLE COSMOLOGICAL DATA

WMAP-7 TEMPERATURE POWER SPECTRUM

LARSON ET AL, ARXIV 1001.4635

LARGE SCALE STRUCTURE SURVEYS - 2dF AND SDSS

SDSS DR-7LRG SPECTRUM(Reid et al ’09)

m = 0.3 eV

FINITE NEUTRINO MASSES SUPPRESS THE MATTER POWERSPECTRUM ON SCALES SMALLER THAN THE FREE-STREAMINGLENGTH

m = 1 eV

m = 0 eV

P(k)/P(k,m

TOTFS

m

kkP

P

8~)(

0

NOW, WHAT ABOUT NEUTRINOPHYSICS?

WHAT IS THE PRESENT BOUND ON THE NEUTRINO MASS?

STH, MIRIZZI, RAFFELT, WONG (arxiv:1004:0695)HAMANN, STH, LESGOURGUES, RAMPF & WONG (arxiv:1003.3999)

DEPENDS ON DATA SETS USED AND ALLOWED PARAMETERS

C.L. 95 @ eV 44.0mUSING THE MINIMAL COSMOLOGICALMODEL

THERE ARE MANY ANALYSES IN THE LITERATURE

JUST ONE EXAMPLE

THE NEUTRINO MASS FROM COSMOLOGY PLOT

Larger modelspace

More data

CMB only

+ SDSS

+ SNI-a+WL

+Ly-alpha

MinimalCDM

+N +w+……

1.1 eV

0.5 eV

~ 0.4 eV

~ 0.2 eV

~ 2 eV 2.? eV ??? eV

~ 1 eV 1-2 eV

0.5-0.6 eV 0.5-0.6 eV

0.2-0.3 eV 0.2-0.3 eV

Gonzalez-Garcia et al., arxiv:1006.3795

WHAT IS N

A MEASURE OF THE ENERGY DENSITY IN NON-INTERACTINGRADIATION IN THE EARLY UNIVERSE

THE STANDARD MODEL PREDICTION IS

3/4

0,0, 11

4

8

7 , 046.3

N

BUT ADDITIONAL LIGHT PARTICLES (STERILE NEUTRINOS,AXIONS, MAJORONS,…..) COULD MAKE IT HIGHER

Mangano et al., hep-ph/0506164

TIME EVOLUTION OFTHE 95% BOUND ONN

ESTIMATED PLANCKSENSITIVITY

Pre-WMAP

WMAP-1

WMAP-3

WMAP-5

WMAP-7

ASSUMING A NUMBER OF ADDITIONAL STERILE STATES OF APPROXIMATELY EQUAL MASS, TWO QUALITATIVELY DIFFERENTHIERARCHIES EMERGE

3+N N+3

s

sA

A

A STERILE NEUTRINO IS PERHAPS THE MOST OBVIOUS CANDIDATEFOR AN EXPLANATION OF THE EXTRA ENERGY DENSITY

Hamann, STH, Raffelt, Tamborra,Wong, arxiv:1006.5276

COSMOLOGY AT PRESENTNOT ONLY MARGINALLY PREFERS EXTRA ENERGYDENSITY, BUT ALSO ALLOWSFOR QUITE HIGH NEUTRINO MASSES!

3+N

N+3

See alsoDodelson et al. 2006Melchiorri et al. 2009Acero & Lesgourgues 2009

• Results for 5.66E20 POT

• Maximum likelihood fit.

• Null excluded at 99.4% with respect to the two neutrino oscillation fit.

• Best Fit Point

(∆m2, sin2 2θ) =

(0.064 eV2, 0.96)

χ2/NDF= 16.4/12.6

P(χ2)= 20.5%

• Results to be published.

E>475 MeV

Richard Van de Water, NEUTRINO 2010, June 14

WHAT IS IN STORE FOR THE FUTURE?

BETTER CMB TEMPERATURE AND POLARIZATIONMEASUREMENTS (PLANCK)

LARGE SCALE STRUCTURE SURVEYS AT HIGH REDSHIFT

MEASUREMENTS OF WEAK GRAVITATIONAL LENSINGON LARGE SCALES

STH, TU & WONG 2006

95% CL

THIS SOUNDS GREAT, BUT UNFORTUNATELY THE THEORETICIANSCANNOT JUST LEAN BACK AND WAIT FOR FANTASTIC NEW DATATO ARRIVE…..

FUTURE SURVEYS LIKE LSST WILL PROBE THE POWER SPECTRUM TO ~ 1-2 PERCENT PRECISION

WE SHOULD BE ABLE TO CALCULATE THE POWER SPECTRUM TO AT LEAST THE SAME PRECISION!

”LSST” ERROR BARS

-1

IN ORDER TO CALCULATE THE POWER SPECTRUM TO 1%ON THESE SCALES, A LARGE NUMBER OF EFFECTS MUST BE TAKEN INTO ACCOUNT

BARYONIC PHYSICS – STAR FORMATION, SN FEEDBACK,…..

NEUTRINOS, EVEN WITH NORMAL HIERARCHY

NON-LINEAR GRAVITY

……………………..

mP

P

6.9~

FULL NON-LINEAR

mP

P

8~

LINEAR THEORY

Brandbyge, STH, Haugbølle, Thomsen, arXiv:0802.3700 (JCAP)Brandbyge & STH ’09, ’10 (JCAP), Viel, Haehnelt, Springel ’10

NON-LINEAR EVOLUTION PROVIDES AN ADDITIONAL AND VERY CHARACTERISTIC SUPPRESSION OF FLUCTUATION POWER DUE TO NEUTRINOS (COULD BE USED AS A SMOKING GUN SIGNATURE)

ANOTHER IMPORTANT ASPECT OF STRUCTURE FORMATIONWITH NEUTRINOS:

THE NUMBER OF BOUND OBJECTS (HALOS) AS WELL AS THEIR PROPERTIES ARE CHANGED WHEN NEUTRINOS ARE INCLUDED

sunM14105

CDM

1 < p/T < 20 < p/T < 1 2 < p/T < 3

3 < p/T < 4 4 < p/T < 5 5 < p/T < 6

512 h-1 Mpc

eV 6.0m

INDIVIDUAL HALO PROPERTIES

Cold Dark Matter

Neutrinos

Brandbyge, STH, Haugboelle, Wong, arxiv:1004.4105

CONCLUSIONS

NEUTRINO PHYSICS IS PERHAPS THE PRIME EXAMPLE OF HOW TO USE COSMOLOGY TO DO PARTICLE PHYSICS

THE BOUND ON NEUTRINO MASSES IS SIGNIFICANTLYSTRONGER THAN WHAT CAN BE OBTAINED FROM DIRECT EXPERIMENTS, ALBEIT MUCH MORE MODEL DEPENDENT

COSMOLOGICAL DATA MIGHT ACTUALLY BE POINTING TO PHYSICS BEYOND THE STANDARD MODEL IN THE FORM OFSTERILE NEUTRINOS